Two cards built for different jobs
Bilt Obsidian ($95/year) and Amex Gold ($325/year) rarely compete for the same dollar. Bilt is the only widely-available card that earns rewards on rent without a processing fee. The Gold earns nothing extra on rent at all — its strength is 4x on dining and groceries.
The rent mechanic that makes Bilt different
Bilt's rent-earning rate isn't fixed — it depends on how much *other* (non-rent) spending you also put on the Obsidian, relative to your rent amount:
| Non-rent spend vs. rent | Rent earn rate |
|---|---|
| Below 25% | 250 points/month flat (baseline) |
| 25%+ | 0.5x |
| 50%+ | 0.75x |
| 75%+ | 1x |
| 100%+ | 1.25x |
So a renter putting $1,800/month in rent on the Obsidian, with at least $1,800/month in other spend also on the card, earns 1.25 points per rent dollar — 2,250 points every month from rent alone, on top of whatever that other spending earns. Put less non-rent spend on the card, and the rent rate drops all the way to a flat 250 points/month. This is exactly the kind of card-to-card interaction the optimizer models directly rather than assuming a single flat rate.
The Gold has no equivalent — there's no rent-tier mechanic to unlock, so rent on the Gold (where the landlord accepts cards at all) just earns the base 1x.
Food spending: choose one vs. get both
- Bilt Obsidian: pick *either* dining *or* groceries for a 3x bonus once a year — not both at the same time. Dining is the default; the grocery option is capped at $25,000/year combined, then drops to 1x.
- Amex Gold: earns 4x on dining (capped $50,000/year combined) *and* 4x on groceries in-store and online (capped $25,000/year each) simultaneously — no annual choice required, and a higher rate than either of Bilt's options.
If your food spending splits meaningfully across both dining and groceries, the Gold's 4x-on-both beats Bilt's pick-one 3x by a wide margin.
What this actually means for your wallet
These two rarely substitute for each other — they usually stack. A renter with meaningful dining and grocery spend commonly ends up running both: Bilt Obsidian to capture points on rent (something almost no other no-fee-processing card does), and the Gold to capture 4x on food. Neither card alone covers what the other does.
The right combination — and whether adding the Gold's $325 fee is worth it on top of Bilt — depends entirely on your rent amount, your other monthly spend, and how your dining and grocery spending splits. Run the optimizer with your real numbers to see the exact routing.
*Data verified as of June 12, 2026.*